How to perform a patch test

The AAD recommends the following steps for patch testing a new skin care product:

  1. Apply the product to a small patch of skin where a person is unlikely to accidentally wash or rub it away. Good areas may include the inside of the arm or bend of the elbow.
  2. Apply the product to a quarter-sized patch of skin. A person should apply the product as thickly as they would when using it regularly.
  3. Leave the product on the patch of skin for as long as it would normally be on the skin. If a person is testing a product that they would usually wash off, such as a cleanser, they should keep the patch on for 5 minutes or as long as the instructions advise.
  4. Repeat the patch test twice a day for between 7–10 days. A reaction may not happen immediately, so it is important to continue applying the product for this length of time.
  5. If a person’s skin reacts to the product, they should wash it off as soon as possible and stop using it. A person can use a cool compress or petroleum jelly to relieve the skin if needed.

Skin care products may contain many different ingredients. Some of these ingredients can irritate a person’s skin or even cause an allergic reaction. By performing a patch test on a small area of skin, a person can see how their skin tolerates a product before committing to using the product over a larger area.